1. Field
The present invention relates to an LED lighting device using a ballast for a fluorescent lamp.
2. Description of Related Art
Recently, a light emitting diode (LED) is increasingly used as a new lighting device in lieu of a filament bulb, a fluorescent lamp and the like and becomes popular. The LED can be driven by a low voltage and has a longer lifespan, lower power consumption, a more rapid response speed and stronger crashworthiness than those of other lighting devices. The LED can be also smaller and lighter. However, since the LED is operated by a very low direct current power and is lighted in a different manner from that of the fluorescent lamp, an ordinary LED lamp cannot be used as it is in a fluorescent lighting system. Basically, a ballast for the fluorescent lamp converts a commercial alternating current power of 60 Hz into a radio frequency of several tens of KHz, and then provides to the lamp. Therefore, not only all the existing fluorescent lighting devices but also the ballast for the fluorescent lamp must be removed in order to use the LED lighting device. If an LED driving circuit is directly connected to a connection terminal of a conventional ballast for the fluorescent lamp without removing the ballast, etc., the LED driving circuit cannot process correctly the high frequency signal or voltage of the ballast, etc., so that the LED lamp is not operated or is destroyed, and the like.
Accordingly, an LED lighting device is recently being developed, which can be directly connected to the ballast for the fluorescent lamp without removing the ballast for the fluorescent lamp.